KTNV-TV, Las Vegas, reported the army of firefighters trying to get the Carpenter One fire on Mount Charleston under control was to expand to more than 600 strong by Saturday evening.
Tony Demasters, deputy incident commander, told the TV station there had been "no accidents, no injuries, no structures lost at this time" in the region endangered by the blaze.
"Those are days we can consider success," he said.
The Carpenter One fire was started by a lightning strike Monday, KLAS-TV, Las Vegas, reported.
Notable deaths of 2014 [PHOTOS]